Wood-borers in Wood Packaging: How Did We Get to This Crisis?

shipping containershipping container being unloaded at Long Beach

The rising numbers of tree-killing wood-boring insects introduced to the U.S. (see  blogs from July 15 and August 3 & fact sheet and sources linked there) are a result of ballooning of trade volumes and use of wood packaging.

This irruption of trade was made possible by adoption of the shipping container to transport a wide range of goods.Moving from place to place are not just finished products but also components that originated in one country and that are to be assembled in another country.

How the shipping container revolutionized trade and manufacturing is detailed by Marc Levinson in his book, The Box: How the Shipping Container Made the World Smaller and the World Economy Bigger (Princeton University Press 2008). The transformation affected not only trade between countries, but also within countries, with some regional economies growing while others faltered.

Dr. Levinson recognizes that he has not addressed environmental damage caused by massive movement of cargo. While Dr. Levinson does not explain which damage he is thinking about, I doubt that he includes introductions of non-native wood-boring pests.

(I don’t know enough about the ballast water pathway to understand the impact of containerized shipping on introductions of aquatic invaders, but it seems likely to be an important factor through three factors: directing trade to new port areas; the ships’ huge size; and taking on of ballast water for those segments of a voyage carrying fewer filled cargo containers. On the other hand, Dr. Levinson says that a balance of cargo moving both ways on a trade route is an important factor in determining which ports thrive.)

Before containers, port costs represented the highest proportion of transport costs. Those costs are no longer an important consideration in determining manufacturing and transport choices. Nor is distance as important as before. What is most important are ports that can move large volumes of goods efficiently. The manufacturer or retailer at the top of the chain finds the most economical place for each step in the manufacturing and assembly process without regard to its location.

The containerization revolution was rapid. Containers were first used in international trade in 1966; within three years, nearly one-third of Japanese exports to the U.S. were containerized, half of those to Australia. In the decade after containers were first used in international trade, the volume of international trade in manufactured goods grew more than twice as fast as the volume of global manufacturing production, 2.5 times as fast as global economic output. Large numbers of specialized container ships were built, at ever-increasing sizes. The largest container ship in 1969 could carry 1,210 20-ft containers. By the early 2000s, ships being built to carry 10,000 20-foot containers; or 5,000 40-foot containers.

When Dr. Levinson wrote his book in 2005, the equivalent of 300 million 20-foot containers were crossing the world’s oceans each year.

The container revolution interacted with “just-in-time” manufacturing, which required rapid and reliable transport. Large companies signed written contracts with suppliers and shippers which included penalties for delays.

In the U.S., Long Beach quickly became the principal port because it (as well as Oakland and Seattle) had excellent rail connections to the interior. By 1987, one-third of containers from Asia destined for the East Coast landed at Long Beach and crossed the U.S. by rail. Perhaps counter to our expectation, only one-third of containers entering southern California in 1998 contained consumer goods. Most of the rest contained intermediate or partially processed goods as part of the new international supply and manufacturing chain.

containers at Long Beach Containers at Long Beach

On the East coast, Charleston SC and Savannah similarly grew because of transport connections – this time, primarily highways.

So, global trade is huge and growing; and the shipping container moves immense quantities of goods from one ecosystem to another and provide shelter for a vast range of hitchhiking living organisms (in addition to insects in the wood, there can be other insects’ eggs attached to the sides of the container, snails, weed seeds, even vertebrates – a raccoon once staggered out of a shipping container that had crossed the Atlantic from the U.S. to France!).

We need to imagine, test, and apply a variety of tools to suppress the numbers of living organisms traveling in shipping containers.

For example,
• if importer-supplier contracts specify penalties for delivery delays, we should ask why don’t importers amend the contracts to add penalties for non-compliant wood packaging?
• Might the Bureau of Customs and Border Protection incorporate the wood packaging requirements into its “Customs-Trade Partnership Against Terrorism” (C-TPAT) program.
• A decade ago, USDA APHIS funded research which developed an ingenious method for detecting mobile pests inside a container. It was an LED light attached to a sticky trap. Placed inside a container, the light attracted snails, insects and possibly other living organisms. The whole mechanism was attached to a mailing container that could be pre-addressed for sending to a lab that could identify the pests. Why was this tool never implemented?

We can’t stop the trade, but we can be much more aggressive in adopting measures to minimize pest introductions.

Posted by Faith Campbell

Non-Native Pest Threat to Forests of the West Coast

As we Americans import more stuff, the risk of new pest introductions rises, too. Many tree-killing insects arrive as larvae living in crates, pallets, and other forms of wood packaging. While the USDA requires that incoming wood packaging be treated to prevent pests, this regulation has not prevented pests from entering the country on wood packaging.

piece of wood packaging with Cerambycid larva; detected in Oregon
piece of wood packaging with Cerambycid larva; detected in Oregon

A study has found that perhaps 35 shipping containers harboring tree-killing pests reach our ports each day (Haack et al. 2014). At this rate, in just 35 years, America might suffer invasion by more than 100 new wood-boring species. This would result in a tripling of borers introduced to U.S. (Leung et al. 2014).

Already, wood-boring beetles have been among the most damaging tree-killing pests introduced to the U.S. Our environment certainly doesn’t need invasions by three times as many new wood-borers!

West-coast ports receive lots of incoming shipping containers. Long Beach alone receives about half of the nearly 25 million shipping containers arriving at the U.S. each year. So it is alarming that high-risk insects, including the Asian longhorned beetle (ALB), continue to be found in wood packaging (Berger 2014).

Imported goods that are heavy are more likely to be packaged in wood and that thus pose the greatest pest risk. The highest risk commodities are
• machinery (including electronics) and metals;
• tile and decorative stone (such as marble or granite counter tops) (Harriger 2014).
The west coast ports of Seattle, Los Angeles/Long Beach, and San Francisco all rank in the top 15 out of 3,500 (1/2 of 1%) cities nation-wide for imports of tile and decorative stone, machinery and metals (Colunga-Garcia et al. 2009).

Not only do west coast cities import high volumes of risky goods; a significant proportion of the trees growing in those cities are vulnerable to these pests. Seattle’s three to four million trees belong to more than 300 species – although a mere seven genera constitute two-thirds of the trees (Ciecko et al. 2012). It has been estimated that just four non-native pests (ALB, gypsy moth, emerald ash borer, and “Dutch” elm disease) could cause $3.5 billion in damages. The ALB alone threatens 39.5% of all trees lining the city’s streets (City of Seattle 2013).

San Francisco has an estimated 669,000 trees; 12% are at risk to the ALB (Nowak et al. 2007). Apparently no one has yet estimated the numbers of trees at risk to sudden oak death (SOD), goldspotted oak borer (GSOB), or polypagous shot hole borer (PSHB).

It is essential that USDA APHIS act more aggressively to prevent additional introductions of pests via wood packaging. (For a longer discussion of the wood packaging pathway, visit my previous blog posted on July 15th). In brief:
• APHIS & the Bureau of Customs and Border protection should penalize all importers whose wood packaging does not comply with decade-old regulatory requirements.
• The Bureau of Customs and Border Protection should incorporate the wood packaging requirements into its “Customs-Trade Partnership Against Terrorism” (C-TPAT) program
• APHIS should re-consider the advantages of requiring importers to switch to packaging made from materials other than wooden boards.
• The President’s Office of Management and Budget should allow APHIS to finalize regulations – proposed in 5 years ago! – that would apply the international standard’s treatment requirements to wood packaging used in trade between the US and Canada. (Canada has been ready to adopt this measure for several years.)

Berger, P. Executive Director, PPQ Science and Technology, Presentation to the Continental Dialogue on Non-Native Forest Insects and Diseases, November 3, 2014

Ciecko, L., K. Tenneson, J. Dilley, K. Wolf. 2012. Seattle’s Forest Ecosystem Values: Analysis of the Structure, Function, and Economic Benefits; August 2012; GREEN CITIES RESEARCH ALLIANCE; City of Seattle Urban Forest Stewardship Plan 2013.

City of Seattle Urban Forest Stewardship Plan 2013.

Colunga-Garcia, M., R.A. Haack, and A.O. Adelaja. 2009. Freight Transportation and the Potential for Invasions of Exotic Insects in Urban and Periurban Forests of the US. J. Econ. Entomol. 102(1): 237-246 (2009); and raw data for the study provided by the authors.

Haack, R.A., F. Herard, J. Sun, J.J. Burgeon. 2009. Managing Invasive Populations of Asian Longhorned Beetle and Citrus Longhorned Beetle: A Worldwide Perspective. Annu. Rev. Entomol. 2010. 55:521-46.

Haack RA, Britton KO, Brockerhoff EG, Cavey JF, Garrett LJ, et al. (2014) Effectiveness of the International Phytosanitary Standard ISPM No. 15 on Reducing Wood Borer Infestation Rates in Wood Packaging Material Entering the United States. PLoS ONE 9(5): e96611. doi:10.1371/journal.pone.0096611

Harriger, K. 2014. Presentation to the Continental Dialogue on Non-Native Forest Insects and Diseases, November 3, 2014

Leung, B., M.R. Springborn, J.A. Turner, E.G. Brockerhoff. 2014. Pathway-level risk analysis: the net present value of an invasive species policy in the US. The Ecological Society of America. Frontiers of Ecology.org

Nowak, D.J., R.E. Hoehn III, D.E. Crane, J.C. Stevens, J. T. Walton. 2007. Assessing Urban Forest Effects and Values: San Francisco’s Urban Forest. USDA Forest Service. Northern Research Station. Resource Bulletin NRS-8.


posted by F.T. Campbell

Alarming Genetic Variability Appears in SOD in Oregon

Oregon authorities have announced that a dying tanoak detected by an aerial survey in the quarantine zone in Curry County, Oregon has proved to be in the EU1 clonal lineage. This is the first report of the EU1 lineage in North American forests. All other isolates of the causative pathogen Phytophthora ramorum in North American forests are the NA1 lineage.  [See below for a discussion of P. ramorum clonal lineages.]



Dying tanoak (in California).  Photo by F.T. Campbell
The infected tree is near a small private nursery that had been reported infested with the EU1 lineage of P. ramorum in 2012. The nursery carried out the APHIS-mandated Confirmed Nursery Protocol, then closed. Genetic testing suggests this nursery is the probable source population for the EU1infestation of the tree.This incident conveys several lessons:

  •  Discovery of the EU1 lineage of P. ramorum in the forest appears to confirm that nursery infestations can infect plants in the forest.
  •  The importance of genetic testing of samples from every infestation to determine which clonal lineage is present.

The discovery has troubling implications: The EU1 lineage consistently is a more aggressive pathogen than the NA1 clonal lineage already present in forests in California and Oregon. The EU1 lineage kills several types of conifer trees in Europe, including western hemlock (Tsuga heterophylla).
Furthermore, the EU1 lineage is of the opposite mating type as NA1, creating at least a small potential for sexual reproduction and increased variability in the pathogen population. (Sexual reproduction in P. ramorum can only occur when opposite mating types meet; in the absence if opposite mating types, all reproduction is clonal.)
The Oregon Department of Forestry is attempting to eradicate this small infestation. Host plants on the infested site have been cut and piled and will be burned as soon as wildfire risk abates. (Burning of other, lower priority sites has been delayed by inadequate funding). Authorities will also continue intensive surveys and will monitor soil and vegetation before and after treatment. Some funding for this work will come from the USDA Forest Service Forest Health Protection program  and USDA-APHIS.
The Phytophthora ramorum pathogen is known to have four separate genetic lineages. The NA1lineage is the form of the pathogen established in forests of California and Oregon. This lineage is also the most common lineage in U.S. nurseries. However, two other genetic lineages are also found in U.S. nurseries: NA2 and EU1 (Coats and Chastagener 2009; Mascheretti et al. 2009). Indeed, NA2 was the most common lineage in Canadian nurseries (Goss et al. 2011).
The EU1 strain is widespread in European nurseries and in tree plantations and wild heathlands of southwest England, Wales, parts of Scotland, and Ireland. In 2012, a new, fourth strain was detected in Northern Ireland and a small area in southwest Scotland. This strain is called EU2.This strain is attacking larch, beech, fir, and hemlock trees at these sites (California Oak Mortality newsletter 2015).

Most EU1 and all EU2 type isolates belong to the A1 mating type, whereas the two North American strains belong primarily to the A2 mating type (Hansen et al. 2003). While P. ramorum apparently reproduces sexually only rarely, the presence of both mating types – in nurseries and especially in forests – does increase the possibility that sexual reproduction will occur. Sexual reproduction would allow the pathogen to evolve and perhaps become more aggressive.


California Oak Mortality Task Force newsletter [http://www.suddenoakdeath.org/news-and-events/newsletter-archive/ ] April 2015.

Coats, K. and G. Chastagener. 2009. Understanding the mechanisms behind detections of Phytophthora ramorum in Washington State nurseries and streams utilizing microsatellite genotype information. Fourth Sudden Oak Death Science Symposium, June 15-18, Santa Cruz, CA.

Goss, E.M., M. Larsen, A. Vercauteren, S. Werres, K. Heungens, and N.J. Grünwald. 2011. Phytophthora ramorum in Canada: Evidence for Migration Within North America and from Europe. Phytopathology. January 2011, Volume 101, Number 1. Pages 166-171

Hansen, E.M., P.W. Reeser, W. Sutton, L.M. Winton, and N. Osterbauer. 2003. First Report of A1 Mating Type of Phytophthora ramorum in North America. Plant Disease, October 2003, Volume 87, Number 10. Page 1267.

Mascheretti, S., P.J.P. Croucher, M. Kozanitas, L. Baker, M. Garbelotto.2009.Genetic epidemiology of the Sudden Oak Death pathogen Phytophthora ramorum in Calif.Molecular Ecology 18: 4577-4590.


Posted by Faith T. Campbell

National Parks Failing to Protect Forests

Americans love their National parks and expect the National Park Service to ensure the parks’ natural resources are protected “unimpaired for future generations” – as is required by the Service’ founding law.
Despite these expectations, the National Park Service does not take obvious actions to protect trees in the parks from non-native tree-killing insects and plant diseases.

Horton House w redbay

Horton House plantation ruins, Jekyll Island, GA.  (Photo by F.T. Campbell) The two large redbay trees shading the house are now gone, killed by laurel wilt.  Use your favorite web browser to see how stark the house is now, denuded of its trees.

At historic sites ranging from Horton House plantation on Jekyll Island, Georgia to the Presidio in San Francisco, trees that create atmosphere & maintain visible links to the past have died.
Even more important is the damage occurring to forests in the “crown jewel” wilderness parks:
• Whitebark pines at high elevations of Yellowstone, Glacier, and Crater Lake National parks have been killed by white pine blister rust (see photo below, of dead whitebark pine at Crater Lake).  Photo by F.T. Campbell


WPBR-Crater L
• The forests of Great Smoky Mountains and Shenandoah National parks, already damaged by chestnut blight, hemlock woolly adelgid, beech bark disease, and gypsy moth, are now losing their ash trees to the emerald ash borer and their walnut trees to thousand cankers disease.
• Everglades National Park and Big Cypress National Preserve are losing their swamp bay trees to laurel wilt [photo from EVER]
• Tanoak trees in Muir Woods, Redwood National Park, and Pt. Reyes National Seashore have been killed by sudden oak death
• Ash trees in Sleeping Bear Dunes National Lakeshore in Michigan have been killed by the emerald ash borer.

Forests in other “crown jewel” parks are not yet under attack, but are threatened by nearby pests:
• The black oak trees of Yosemite National Park’s signature Valley are at risk to goldspotted oak borer, which has killed more than 100,000 trees in San Diego county.
The threat is obvious … yet the National Park Service dropped efforts to develop a strategy for addressing it. And the NPS has not adopted a national policy requiring campers to obtain their firewood either in the Park or from nearby vendors.
As explained on the Don’t Move Firewood website, firewood is a highly dangerous commodity, since it can transport tree-killing pests to new, vulnerable areas [see also the report Fading Forests III. Some National parks – including Great Smoky Mountains and Shenandoah – have adopted regulations prohibiting visitors from bringing firewood from long distances. However, other parks – including Yosemite – only ask visitors to avoid bringing firewood. In all cases, the firewood regulation or appeal is buried deep within the park’s website. On a more positive note, campers who reserve a campground on such federal websites as www.reserve.gov receive warnings about firewood when they finalize their reservation.
The National Park Service has developed a Manual  providing guidance to park managers that describes the threat from firewood and laws and regulations that relate to natural resource protection. However, the Service has left the decision whether to take action to the individual parks’ superintendents.
I think that such a passive stance betrays the Service’ statutory obligation, as laid out in the Organic Act of 1916: the purpose of the National Park Service is
“to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations.” [emphasis added]

Next year, the National Park Service celebrates its Centenary. I think it should celebrate this anniversary by adopting regulations requiring visitors to obtain firewood locally and finalizing a strategy for combating tree-killing pests.